Open reduction of subcondylar fractures via an anterior parotid approach

Visualization of subcondylar fractures is limited, and rigid fixation technically difficult, employing standard open surgical techniques--especially when the condyle is displaced out of the glenoid fossa. The majority of condylar neck fractures are treated by closed reduction with maxillomandibular fixation, to obviate the potential for permanent injury to the facial nerve. The technique described employs an anterior parotid, two-layer, sub-SMAS (superficial musculo-aponeurotic system) approach via a rhytidectomy incision that reliably identifies and preserves the neural elements and provides direct access to the pericondylar region. The thirteen patients presented here exhibited satisfactory functional and aesthetic results. Complications included temporary nerve palsies, plate fractures, and a hematoma.

Traumatic chronic TMJ dislocation: report of an unusual case and discussion of management

Dislocation of the temporomandibular joint (TMJ) is most often spontaneous, but it can be associated with direct or indirect head and neck trauma. The disorder may be treated in general by simple closed techniques, if managed acutely. If the dislocation becomes chronic, however, open reduction is usually required. The article discusses various methods for an open surgical approach described in the literature. A case of a prolonged TMJ dislocation is presented, involving a severe bilateral mandibular dislocation with the condyles displaced into the infratemporal fossa and the lateral poles of the condyles articulating on the inner aspect of the zygomatic arch. An open approach, involving masseter, temporalis, and the medial pterygoid muscles, was utilized, followed by the use of scissors mouth props, Erich arch bars, and postoperative elastic traction.

Regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in lambs

We investigated the degree of regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in growing lambs. Four 10-week-old lambs had unilateral condylectomy and myotomy of the superficial layer of the masseter on the right side, and were killed 3 months later. The joints were examined radiologically and histologically. All joints showed poor regeneration of the condylar head. In the medial plane there was partial condylar and articular cartilage reformation, but in the lateral plane there was neither condylar nor cartilaginous reformation. The articular cartilage of the temporal bone was thicker in the medial plane and the disc was thicker in the central plane, than in unoperated joints. We conclude that unilateral condylectomy and myotomy of the masseter in the growing period results in poor regeneration of the condyle.

Deep middle masseteric artery (dMMA) attributed to hemorrhage in resection of masseter muscle and mandibular angle

This study aimed to investigate pertinent arterial supplies of masseter muscle to prevent fatal hemorrhage in resection of masseter muscle and/or mandibular angle ostectomy. Fifty-three postmortem cadavers of Koreans were used for the work. Color latex was injected into the arteries to outline 17 of 53 specimens. We found that an artery branches off the external carotid artery and enters the masseter muscle at the midpoint of its posterior margin 31 mm above the gonion. We termed this the middle masseteric artery. The middle masseteric artery is divided into superficial and deep branches. The deep branch of the middle masseteric artery travels deep in the muscle close the periosteum of the mandible in 94% of cases. The average diameter is 1.23 +/- 0.26 mm. A small artery with 1.23-mm diameter is enough to cause massive bleeding if severed. The deep branch of the middle masseteric artery is vulnerable in such procedures as resection of the masseter muscle and/or ramus and angle of the mandible.

Temporoparietal-occipital flap for facial reconstruction

Eight patients with an extensive facial defect of the masseter region were reconstructed with a temporoparietal- occipital rotation flap. This flap is vascularized by both the arteria auricularis posterior and the arteria occipitalis lateralis. These vessels have been sufficient to ensure viability of the entire flap. It is elevated and easily transposed to the masseter region because of the distensibility obtained from the posterior neck. This approach avoided the need for an unsightly skin graft at the site while providing tissue with hair follicles that blend well with the surrounding hair. This large flap offers cosmetic advantages over other techniques for coverage of facial defects in men.

Release of extra-articular ankylosis by coronoidectomy and insertion of a free abdominal flap: case report

INTRODUCTION

It is generally agreed that an effective treatment for extra-articular ankylosis may be coronoidectomy and excision of scar tissue. But these conventional procedures have shown a high rate of recurrence of ankylosis due to heterotopic bone and fibrous tissue formation. OBJECTIVE AND PATIENT: We report a case in whom a coronoid osteotomy and insertion of a free abdominal flap was used to treat ankylosis of the mandible following radiotherapy for maxillary cancer.

RESULTS

This procedure prevented recurrence of ankylosis by heterotopic bone and fibrous tissue formation. In addition, this flap reduced the risk of postoperative infection and promoted primary healing.

CONCLUSION

The procedure, coronoidectomy and insertion of a free flap, was successful because the well-vascularized musculocutaneous flap occupied the dead space, and replaced the shortage of oral mucosa consequently inhibiting the recurrence of extra-articular ankylosis.

[Intramasseter hemangiomas: a case report]

Intramuscular hemangiomas are uncommon tumours in the head and neck region, especially in the masseter muscle. This article presents a case of a 10-year-old male treated by surgical excision. The authors review the literature to discuss the clinical characteristics, sex, age, differential diagnosis, surgical approaches, and histology.

Prolonged mandibular hypomobility patient with a "square mandible" configuration with coronoid process and angle hyperplasia

The objective of this study was the surgical management of chronic severe mandibular hypomobility patients associated with square mandible morphology with coronoid process and angle hyperplasia, and one-year follow-up data is reported. Ten patients were studied. All patients were female and had a history of gradual severe jaw hypomobility. Clinical findings were similar to those of a "closed lock" patient. However, the facial appearance in these patients showed a characteristic square mandible facial configuration. Coronoid process thickening and overgrowth of the mandibular angle was evident in the radiographic findings. Diagnostic imaging scarcely depicted any disk derangement, but a severely limited jaw opening was noted in spite of acceptable excursive jaw movements. Bilateral coronoidotomy or coronoidectomy was done initially, and then masseter muscle stripping via the intraoral approach. After successful reduction of jaw hypomobility, a selective mandibular anglectomy was completed. Physical therapy began within three to five days after the surgery. Postoperatively, all patients were questioned about their jaw function and their subjective assessment of the treatment. Interincisal jaw opening was recorded with a ruler marked in millimeters. Bilateral coronoidotomy or coronoidectomy and masseter muscle stripping were done for all patients; the mandibular anglectomy was performed in seven of the cases at 13 sites. Simultaneous TMJ surgery was done on three joints for three patients. Most patients reported improvement of jaw function, and the patients' subjective assessment revealed an average satisfaction rate of 74.6%. A preoperative mean jaw opening distance of 25.6 mm increased to 36.6 mm postoperatively at a one-year follow-up (p < 0.05). The conclusion was that surgical intervention is indicated when nonsurgical treatment is unsuccessful. Etiology is unknown, but masseter and temporal muscle contracture associated with mandibular coronoid and angle hyperplasia may be a strong component of the pathophysiology.

[Venous malformation of the corpus adiposum buccae]

We report on a venous malformation (previously known as a cavernous angioma) with an unusual location in the corpus adiposum buccae. Diagnosis, histologic classification and management of these rare lesions are discussed.

Condylar changes after contralateral mandibular osteotomy in the rabbit

Following orthognathic surgery undesirable changes in the temporomandibular joints (TMJs) are noted sometimes. Altered stress on the condyle and surrounding tissue frequently causes morphological changes in the TMJ. The purpose of the present study was to assess these morphologic changes in a rabbit following mandibular osteotomy and the resulting mandibular body rotation. Adult male Japanese white rabbits (3 kg, 12-16 weeks old) were applied in this study. An experimental mandibular osteotomy was performed on the right side of the body of the mandible. The surgery includes vertical mandibular body osteotomy 5 mm in width after masseter muscle reflection. Then the anterior and posterior osseous segments were fixed with wire at previously made holes. As a result, the condylar medio-lateral width on the contralateral (left) side was significantly larger than that of the ipsilateral side 2 weeks postoperatively (p < 0.05). There were significant differences in the angle between the right and the left condylar heads 4 weeks postoperatively (p < 0.05). The present experimental study demonstrated morphological changes in the contralateral TMJ caused by unilateral mandibular osteotomy. Postoperative morphological changes implied that there is a process of biological adaptation in the rabbit TMJ.

Masseteric hypertrophy?: preliminary report

We report radiological and histological investigations of a patient who presented with the masseteric hypertrophy. Sections of the patient's masseter muscles were also investigated using a series of histological techniques. The histological and morphometric analysis of the patient's masseter muscle showed numerous small fibres, which indicated that the masseteric enlargement was not the result of classic fibre hypertrophy. We suggest that the use of the term 'hypertrophy' in this condition may be misleading.

Muscle bow traction method for dynamic facial reanimation

A muscle bow traction method was developed for dynamic facial reanimation utilizing the masseter muscle and a fascial sling. The principle of this method is that the sling around the muscle pulls the oral commissure laterally and backward by the restoring force of the muscle from its relaxed position to its contracted position. The surgical procedure is simple. The sling is passed around the anterior half of the muscle so that the muscle can be bowed anteriorly at its center by the sling. One end of the sling is sutured to the center of the orbicularis oris and the dermis in front of the nasolabial fold, and the other end is sutured to the lower lip and oral commissure. This method was applied to 3 patients with facial palsy and to 1 patient with oral cancer. The restored motion of the oral commissure ranged from 5 to 8 mm when clenching the jaws. The concept of this method differs from those of other muscle transposition methods for facial reanimation in that the force acts at a right angle to the muscle contraction. The advantage of this method is that it is less invasive to the muscle and is a simpler procedure than other conventional muscle transposition methods.

Diagnosis and surgical treatment of periapical infection of the third mandibular molar in five horses

Diagnosis and treatment of periapical infection of the third mandibular molar in 5 horses was assessed. In 4 of 5 horses, there was a recent history of dental work performed. Diagnosis required multiple imaging techniques. Radiography revealed evidence of periapical bone lysis or tooth root lysis of the third mandibular molar in 3 of 5 horses. Sonographic examination was effective in identifying abscesses within the masseter muscle and defects of the lateral cortex of the mandible in 4 of 5 horses. Nuclear scintigraphy was diagnostic in 1 of 2 horses examined. All horses were treated by repulsion of the affected tooth. The surgical approach involved elevating the masseter muscle from the caudal portion of the mandible. This approach provided excellent access to the affected tooth with minimal postoperative complications. All incisions healed with good cosmetic results.

Intramuscular hemangioma of the masseter muscle

Intramuscular hemangiomas (IMH) are uncommon tumors of the head and neck, but often occur in the trunk and extremities. When present in the head, the masseter muscle is the most frequently involved site, although constituting only 0.8% of all hemangiomas. Accurate preoperative diagnosis is uncommon without cytology or biopsy. A case of IMH of the masseter muscle in a 24-year-old Turkish woman is presented. Clinical, radiologic and histologic findings and treatment modalities are reviewed.

Congenital trismus secondary to masseteric fibrous bands: endoscopically assisted exploration

The authors present an 18-month-old female infant with congenital trismus. Computed tomography and magnetic resonance imaging were not helpful in determining the cause. A surgical endoscope was used to explore her temporomandibular joints and temporal fossae, thus avoiding the morbidity of a bicoronal incision. The cause was bilateral fibrous bands on the anterior border of the masseter muscles. Incision of these fibrous bands led to relief of the trismus. This finding is consistent with a previously described variant of the Hect-Beals-Wilson trismus-pseudocamptodactyly syndrome. This patient, however, had no evidence of the autosomal dominant inheritance pattern nor did she exhibit pseudocamptodactyly, both of which are generally ascribed to this syndrome. Unfortunately the trismus recurred 3 months postoperatively.

Electromyographic activity of the jaw-closing muscles before and after unilateral coronoidectomy performed on a patient with coronoid hyperplasia: a case study

There have been few reports analyzing the activity of the jaw-closing muscles after coronoidectomy performed on a patient with coronoid hyperplasia. This paper presents a case study using electromyograms (EMGs) to evaluate the effects of unilateral coronoidectomy on the activity of masseter and temporal muscles. The patient was a 25-year-old male whose maximal range of jaw opening was 24 mm. After coronoidectomy of the left region, the range improved to 43 mm. EMGs were recorded in the center of the masseter muscles and the anterior part of the temporal muscles during gum chewing. Preoperatively, no abnormal EMG activity was observed. Eight months after surgery, increase in the ratio of the bilateral temporal muscle activity and a decrease in the ratio of the right masseter muscle activity were observed, and the proportion of activity of jaw closing muscles was out of the normal range. Eighteen months after surgery, there was slight return to the preoperative EMG activity. It was concluded that unilateral coronoidectomy could result in EMG changes of masseter and temporal muscles with a gradual return.

[Exposure of the facial nerve in the masseteric region during parotid surgery. Technical aspects and value]

With an accurate understanding of facial soft-tissue anatomy, deep plane rithydectomy can be performed in safe and precise fashion. We report our experience of 19 cases of parotidectomy using this superficial musculo-aponeurotic system mobilization anterior to the gland. In all cases (two recurrences), it was thus possible to safely expose at least two terminal branches of the lower facial nerve in the masseteric area without jeopardizing the facial nerve. During a second operation for recurrent tumor or in the case of some lesions as inferior and anterior intraglandular cyst, the distant branches of the nerve can be uncovered by a backward dissection. The easiest to identify seems to be the terminal branches in the masseteric area, as it is directly accessible after cutaneous undermining in an area generally not dissected during previous operations and with preserved anatomic relations. In other cases this technique enables one to expose the parotid gland completely and facilitates anterograde facial nerve dissection by its terminal exposure. The superficial musculo-aponeurotic system dissection allows its backward transposition, in the absence of any contraindication, so as to prevent retromandibular depression following a parotidectomy.

[Recent progress in facial esthetic surgery (excluding endoscopic technics)]

Recent advances offer a new approach to cosmetic surgery of the frontal, cervico-facial and orbito-palpebral areas. Conservative frontal lifting procedures displace the entire frontal muscle (without section or resection) over the underlying bone and periosteal planes by raising the galea and the antagonist muscles. This repositioning reduces or eliminate wrinkles by preventing hyperfunction of the frontal muscle. The risk of sensorial or motor nerve lesions is reduced and the forehead and eyelids have a natural appearance. Unlike extensive lifting of the cervico facial areas, physiological conservative cervico-facial lifting maintains the cutanéomusculo-aponeurotic unity which associates the skin with the superficial musculo-aponeurotic system. The procedure limits detachment in the parotido-masseter region. Early results on the lower cheeks and platysmal cords are significant. The absence of cutaneous detachment preserves the natural appearance of the palpebral complex and the orbital fat allowing improved function and a pleasant aspect of the eyelids. This surgery should be widened beyond the orbito-palpebral area and be used in the frontal, jugal and, in certain cases, the endonasal areas.

[Correction of square face]

OBJECTIVE

This work was to provide an advanced operation method for square face correction.

METHODS

The method is characterized by resecting hyperostosis of the mandibular angle, the bulky masseter and the buccal fat pad through intraoral or combined extra-intraoral approach.

RESULTS

Good results were obtained in 10 cases after follow-up of 4 to 28 months.

CONCLUSION

This operative method proved to be quite ideal and applicable to treat square face.

[Measurement of mandibular angle protrusion and semi-blind amputation of hypertrophied mandibular angle with the help of a pre-made mold]

OBJECTIVE

Mandibular hypertrophy is a subjective diagnosis to some extent. The authors tried to find a way for true objective diagnosis of mandibular hypertrophy.

METHODS

Radiographic cephalometry was performed in 39 randomly selected adults. The degree of the mandibular angle was measured and summarized. According to measurement of the mandibular angle and the extent to be amputated, we designed and made various molds.

RESULTS

With this pre-made mold, we amputated semi-blindly and exactly the desirable size and shape of the mandibular angle. This technique has been used in 6 patients for mandibular amputation and masseter thinning. In three patients shaving of the out layer of the hypertrophied mandible was also done.

CONCLUSION

The new technique using the pre-made operative mold shortens operating time, reduces surgical bleeding and tissue swelling, and can help to remove the bony block precisely.

[Experimental microsurgery of the facial nerve: end-to-end suture versus approximated ends wrapped with masseter muscle aponeurosis]

As an alternative to end-to-end facial nerve microsurgery, we propose anastomosis of the sectioned nerve ends and wrapping with ipsilateral masseter fascia. This intervention was performed on the right facial nerve of 20 Wistar rats and compared with classical end-to-end anatomosis performed on the left nerve of the same rats. At the end of the experiment, histological studies were made of each nerve removed "en bloc" with the ipsilateral lip orbicular muscle. Five micra-thick sections were stained using conventional and immunohistochemical methods. We analyzed truncal integrity, fibroblast proliferation, demyelination, lymphocyte proliferation, granulomatous reaction, and muscle degeneration in both types of anastomosis. The differences between the two types of anastomosis were statistically non-significant, and both interventions produced similar functional results. Small differences between the techniques might condition the use of one or the other in selected cases.

Myositis ossificans traumatica of the masseter muscle: review of the literature and report of two additional cases

Myositis ossificans traumatica of the masseter muscle is uncommon. The condition is benign and results in reactive heterotopic bone formation, usually producing limitation of opening of the jaws. Radiographic and microscopic examination can confirm the diagnosis. Treatment of myositis ossificans traumatica of the masseter muscle is surgical, with other modalities used when occurring in other muscles of the body.